a. Field of Invention
This invention relates to novel processes for the production of N-(2-alkoxy-1-naphthoyl)glycine esters. The N-(2-alkoxy-1-naphthoyl)glycine esters produced by the present processes are themselves useful intermediates for the manufacture of N-naphthoylglycine derivatives having aldose reductase inhibiting activity and which are useful for treating diabetic complications. Said aldose reductase inhibitors are described in copending patent application AHP-9141, incorporated herein by reference.
More specifically this invention relates to the process for the production of N-[[2-alkoxy-6-methoxy-5-(trifluoromethyl)-1-naphthalenyl]carbonyl-Nmethyl glycine esters of formula (I) ##STR1## wherein R.sup.1 and R.sup.2 are lower alkyl or aryl(lower)alkyl, wherein lower alkyl contains 1 to 6 carbon atoms.
b. Prior Art
The closest prior art to the present invention is Sestanj et al, U.S. Pat. No. 4,439,617, March 27, 1984; and Sestanj et al, U.S. Pat. No. 4,568,693, February 4, 1986. Sestanj et al disclosed processes for preparing N-naphthoylglycine esters which are intermediates in the preparation of compounds which inhibit aldose reductase, but which lack a 2-alkoxy substituent on the naphthalene ring.